Revert "Remove recents tasks limit"

This reverts commit 08f8342375264c9d21049257a92fef5d5a253c83.
Revert "Fix notifications button and recents tasks limit number"

This reverts commit 8b18fe2295625a6de3f2c1ae185aa1d9b78f40d1.
Revert "QS also apply for status bar expand"

This reverts commit e1f10866a145904b80169b58cadaab18f6bc5329.
Revert "Add QS auto default and recents tasks limit"

This reverts commit d81e3e4a032ae52210f228802edaee1462e0a081.
SystemUI: Option to display Quick Settings when there are no ongoing notificaions

Added member function hasClearableNotifications to class
PhoneStatusBar. This function returns true when clearable
notifications are present on the status bar. Also, onTouchEvent in
NotificaionPanelView now flips to Quick Settings if there are no
ongoing notifications, and the QS_QUICK_PULLDOWN is set accordingly.

Change-Id: Ia77f90b19c7b408b7fc9376b6914e3173b734655